Several mission critical products in military and aerospace applications require high-precision controllers on switched reluctance machines in order to function safely and properly. (“reluctance motor” and “reluctance machine” are used interchangeably). A majority of controllers in use today assume an ideal inductance profile while ignoring mutual effects. However, an ideal analytical model needs to incorporate up-to-date information about machine dynamics including a very accurate parameter identification and compensation technique.
The design, control and analysis of a switched reluctance machines require detailed information about the flux-linkage characteristics of the windings for various rotor positions and current levels. Presently, research conducted towards estimation of torque, position and other machine parameters for the switched reluctance machine tend to ignore the effects of mutual coupling between different phases owing to the concentrated windings around the stator poles. The effects of mutual inductance on the performance of the machine have been addressed by researchers in the past. For example, Moghbelli et al. reported an error up to 7% in the estimated flux-linkage owing to this approximation.
While these assumptions may be reasonable in a few industrial applications, they cannot be used for high performance systems, such as military and aerospace applications. It follows that a more accurate model of the switched reluctance machine is desirable which eliminate said errors. Ideally, it is desired to obtain the mutual inductance using terminal measurements (i.e. voltages, currents and time) with no extra hardware or memory.